The present invention in various embodiments relates generally the gloss inherent in the hardcopy text or text/like objects. More particularly, this invention relates to halftoned image data and the control of differential gloss when that halftone image data is printed into hardcopy. This invention further relates to the design of a font where the characters, symbols and other font elements are recognizable predominantly by gloss differentiation.
It is desirable to have a way to protect against the copying of a document. Most desirably in a manner so that part of the content can be readily observed by a human reader but not by a copier scanner. It is desirable that such a solution also have a minimum impact in its digital processing overhead requirements as well as minimizing any storage requirements. Additionally, it is highly desirable that this solution can be obtained without physical modification to the printing device and without the need for special materials and media.
There has been a need for a printer that can print a page that can be read but not copied. One approach is where a text string is printed using clear toner or ink, creating a difference in reflected light and diffused light that can be discerned by a human reader by holding the paper at an angle, but can not typically be detected by a copier scanner which is restricted to reading at fixed angles to the page. Such an approach provides a gloss image of the font string. Unfortunately, this approach requires clear toner or ink.
Another method, described in U.S. Pat. Nos. 4,210,346 and 5,695,220, is to use a particular white toner and a particular white paper that are designed to have different diffused light characteristics at different angles. Of course, this system requires special, matched paper and toner.
In U.S. Pat. No. 6,108,512 to Hanna, there is illustrated, for example, a system for producing non-copyable prints. In a xerographic printer, text is printed using clear toner. Thus, the only optical difference between toner and non-toner portions of the page is in the reflectivity. The plastic toner will reflect more light than the paper. A human reader can now read the image by holding the page at such an angle that the eye will intercept the reflected light from the toner, producing a contrast between the lighter appearing toner and the darker appearing paper. However, a copier scanner is always set up to avoid reflected light, by supplying light at an oblique angle and reading at a right angle. In this case, the diffused light is approximately equal for both toned and untoned surfaces, the scanner will detect no difference and the copier will not be able to copy the original. Here again, special material is required.
Another approach taken to provide a document for which copy control is provided includes digital watermarking. As an example in U.S. Pat. No. 5,734,752 to Knox, there is illustrated a method for generating watermarks in a digitally reproducible document which are substantially invisible when viewed including the steps of: (1) producing a first stochastic screen pattern suitable for reproducing a gray image on a document; (2) deriving at least one stochastic screen description that is related to said first pattern; (3) producing a document containing the first stochastic screen; (4) producing a second document containing one or more of the stochastic screens in combination, whereby upon placing the first and second document in superposition relationship to allow viewing of both documents together, correlation between the first stochastic pattern on each document occurs everywhere within the documents where the first screen is used, and correlation does not occur where the area where the derived stochastic screens occur and the image placed therein using the derived stochastic screens becomes visible.
For each of the above patents and citations the disclosures therein are totally incorporated herein by reference in their entirety.
As disclosed in U.S. Patent Publication No. 2003/0231349 entitled “HALFTONE IMAGE GLOSS CONTROL FOR GLOSSMARKS”, to inventors Shen-ge Wang, Beilei Xu, and Chu-heng Liu (cross referenced and incorporated above), there is provided an arrangement and methodology which will control gloss and allow manipulation for Glossmark™ differential gloss images without requiring special toners/inks or paper/substrates, nor require the superimposition of additional prints to allow viewing. However, with such an arrangement and methodology, there is inherent a requirement for additional electronic processing beyond that otherwise normally needed. There may also be increased storage requirements entailed as well. A typical scenario for variable data is in the area of mass mailing where mail fliers are personalized “on-the-fly” with variable data inserted into provided fields in the document as the document is hardcopy printed. As will be well understood by those skilled in the art any undo image data processing overhead would unacceptably impact the printing process. It would therefore be desirable to minimize the impact of such required additional electronic processing with a variant providing a further improved methodology for the manipulation of inherent differential gloss.
As further disclosed in U.S. Patent Publication No. 2004/0000786 entitled “VARIABLE GLOSSMARK”, to inventors Shen-ge Wang, Beilei Xu, and Chu-heng Liu (cross referenced and incorporated above), there is provided an arrangement and methodology which relates to the segmentation of an image into a main area and a image segment for the sake of providing variable Glossmark™ differential gloss image data. By selectively applying halftones with anisotropic structure characteristics which are significantly different in orientation while remaining identical in density to the image segment, a variable Glossmark™ differential gloss image may be superimposed within an image with reduced processing and storage requirements. However, the basic creation of variable data Glossmark™ differential gloss image areas in a hardcopy page (as well as correlation marks in general) must start by combining a primary image with a desired variable image data provided as required in a Glossmark™ differential gloss image scenario as binary mask data. In the portions of the image selected by the binary mask data one halftone screen is used. In other portions of the image an alternate halftone screen is used. Thus, it follows that two data channels need to be combined where one data channel controls the halftone fine structure and the other data channel delivers the image content. In standard DFEs (digital front-ends), as provided in copiers, printers, multifunction devices, or digital presses, these channels are simply not available—nor is IOT (image output terminal) access for the halftoning commonly accessible at this level—so that the complete Glossmark™ differential gloss image or other correlation mark must be created off-line and inserted. This effectively impedes the ability for creation of Variable Data Glossmark™ differential gloss images, particularly on-the-fly in a digital press mass mailing scenario, since all images must be computed externally. This causes several problems in data flow, data handling, and data bandwidth particularly for variable data systems. Described herein below is an approach for solving this problem.
Disclosed in embodiments herein, is a method for variable data differential gloss font control. The method comprises segmenting each font element into two areas and incorporating a anisotropic structure to each of the two areas, where the two anisotropic structures are predominantly orthogonal to each other.
Further disclosed in embodiments herein, is a method for variable data differential gloss font control comprising the design of a font whose elements are predominantly recognizable by varying gloss, rendering all characters/symbols in the described manner and encapsulating the rendered elements into a new derivative gloss font. A font format that is efficiently handled by a DFE (Digital Front End) such as DocuSP® and using said font in a variable data application such as VIPP® (Variable Data Intelligence Postscript Printware).
Further disclosed in embodiments herein, is a method for variable data differential gloss image control comprising segmenting the creation of a font encapsulating the different characters/symbols predominantly as gloss differences. The method comprising rendering a rectangular field area with one of two anisotropic halftone structures, using a predetermined gray level, rendering into this rectangle at identical gray level a character/symbol using a second halftone structure at different angle from said first structure. The method further comprising encapsulating the rendered rectangle as part of a new gloss font. The method finally comprising using the so created gloss font as font in a document production system, preferably a variable data document production system.
Further disclosed in embodiments herein, is a method for a variable data differential gloss font image comprising, selecting a font character, sub-sampling that selected font character into a sub-sample result and scaling that sub-sample result back up to a desired full size result. Selection is made of a first halftone cell having a first anisotropic structure orientation and a second halftone cell having a second anisotropic structure orientation. The first halftone cell is applied to the desired full size result and the second halftone cell is applied to the background field for the desired full size result to produce a variable data differential gloss font image.
Further disclosed in embodiments herein, is a method for generating a variable text data differential gloss font image set comprising, selecting a font character and rasterizing that selected font character into a bit-mapped sub-sample result. This sub-sample result is scaled back up to a desired full size bitmap result having a bit pattern defined therein. Selection is made of a first halftone cell having a first anisotropic structure orientation and a second halftone cell having a second anisotropic structure orientation. A background field area suitable for encompassing the selected font character is selected as well. The selected first halftone cell and the second halftone cell are applied to the selected background field area, toggling between the selected first and second halftone cells as dictated by the bit pattern in the desired full size bitmap result to create a differential gloss font character image. The differential gloss font character image thus created is stored for utilization as system font.